分类: 生物学 >> 生物物理学 >> 生物物理、生物化学与分子生物学 提交时间: 2016-05-12
摘要: The homeostasis of magnesium (Mg2+), an abundant divalent cation indispensable for many biological processes including mitochondrial functions, is underexplored. Previously, two mitochondrial Mg2+ importers, Mrs2 and Lpe10, were characterized for mitochondrial Mg2+ uptake. We now show that mitochondrial Mg2+ homeostasis is accurately controlled through the combined effects of previously known importers and a novel exporter, Mme1 (mitochondrial magnesium exporter 1). Mme1 belongs to the mitochondrial carrier family and was isolated for its mutation that is able to suppress the mrs2 Delta respiration defect. Deletion of MME1 significantly increased steady-state mitochondrial Mg2+ concentration, while overexpression decreased it. Measurements of Mg2+ exit from proteoliposomes reconstituted with purified Mme1 provided definite evidence for Mme1 as an Mg2+ exporter. Our studies identified, for the first time, a mitochondrial Mg2+ exporter that works together with mitochondrial importers to ensure the precise control of mitochondrial Mg2+ homeostasis. (C) 2015 Elsevier B.V. All rights reserved.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Two novel twisted anthracene derivatives, 2-(4-(10-(phenanthren-9-yl)anthracen-9-yl)phenyl)-1- phenyl-1H-phenanthro[9,10-d]-imidazole (p-PABPI) and 2-(3-(10-(phenan-thren-9-yl)anthracen-9-yl) phenyl)-1-phenyl-1H-phenanthro-[9,10-d]imidazole (m-PABPI), have been synthesized. Their photo- physical and photochemical properties are also investigated systemically. The non-doped fluorescent organic light-emitting diodes are fabricated by using anthracene derivatives as the emitters. The maximum current efficiencies are achieved to be 3.98 and 1.32 cd A 1 and the maximum power effi- ciencies are 2.80 and 1.14 lm W 1, respectively. The external quantum efficiency maximum (EQEmax) is 3.61% and 1.33% for p-PABPI and m-PABPI. Intriguingly, the efficiencies of p-PABPI are almost three times larger than that of m-PABPI with only the different molecular configuration. The results revealed a new rule of molecular design based on anthracene derivatives for obtaining high performance blue emission materials.
分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: The hard X-ray micro-focusing beamline (BL15U1) of SSRF is dedicated to hard X-ray micro/nano-spectrochemical analysis consisting of X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques. It is one of the most versatile instruments in hard X-ray microscopy science. Since its commission in 2009, BL15U1 has allocated over 25000 h beamtime for users, and about 700 proposals have been executed. The beamline and the experimental end-station were upgraded for several times to facilitate the users experimental needs and make it more convenient to operate. In this paper, we give a review on the beamline, describing its characteristics, recent technical developments, and a few examples of scientific progresses achieved in recent years on BL15U1.